Analyzing On Environmental Quality Improving And Economical Efficiency By Wet Flue Gas Desulfurization System In Power Plant

This study has important theoretical and practical significance to assess the wet flue gas desulphurization (WFGD) system of coal fired power plant scientifically to improve the environmental quality and its economy, keep the FGD system can run effectively, and make effective FGD compensation policy to achieve the goal for reducing emissions and conserving energy.At first, the paper studies on assessing methods of environmental quality and its economy, and the desulphurization system of coal fired power plant research status on its application. It analyzes the achievements and deficiency. The paper introduces the related theory and methods that is. methods of environmental quality assessment, cost-effectiveness analyzing method, and sensitivity analysis, fuzzy pattern recognition, etc. The paper introduces the technical principle of WFGD. the institutes of system, main equipments, the deficiency in technical application of WFGD of coal fired power plant in China, and the influence on surrounds environment of power plant. Aiming at the deficiencies of assessing method about environmental quality of current coal fired power plant and the application of the fuzzy pattern recognition method, the paper puts forward the improving method of neartude function and using improved neartude function. It puts forward on the new assessing method of environmental quality of coal fired power plant based on fuzzy pattern recognition, and proves its feasibility by application. The paper puts forward on two indicators about the improvement of assessing environmental quality, that is, environmental quality improving value and environmental quality improving degree. It defines the concept of ideal target of environmental quality improvement and its computing method. Based on this, it puts forward on the computing method of environmental quality improving value and environmental quality improving degree. They can calculate the environmental quality improving effect by desulphurization system quantitatively. A practical example proves its feasibility and scientific nature. The paper analyzes the structure of cost and effectiveness in WFGD of power plant using cost-effectiveness analysis method. They include the initial fixed investment, desulphurization agent consumption charge, and the consumption charges of water, power and steam in desulphurization system, fixed assets repairing cost, labor cost, saving and SO2emission charge, and gesso sales revenue etc. The paper puts forward the calculating methods of cost-effectiveness, total cost present value, cost-benefit ratio and net cost present value in each lifetime of the desulphurization system, and the sensitivity analysis on the economy of desulphurization system according to the factors, that is, power generating hour of power plant, the price of limestone and feed-in tariff. Combining with the desulphurization system of a power plant proves its feasibility. The paper puts forward the indicators for assessing the effectiveness economy of improving environmental quality of the desulphurization system. They are the environmental quality improving value per net present value, the environmental quality improving degree per net present value, net present value of per environmental quality improving degree. It gives the computing method about the three indicators, that is, application environmental quality improving value, environmental quality improving degree and net cost present value. It puts forward an analyzing method by using the indicators of the economy of desulphurization system and the economy analysis method of the environmental quality improving effect under the compensation policy on the desulphurization electricity price. And it puts forward the method of sensitivity analyzing on the indicators of the economy of desulphurization system and the economy of the environmental quality improving effect under the changes of power generating hour and the price of sulfuric acid. By using aforementioned methods, the paper assesses the economy of environmental quality improving effect by a power plant desulphurization system, and proves the feasibility of the methods. Finally, it gives some advice about the policy to build dynamic desulphurization electricity price mechanism and improving the economy of WFGD, based on aforementioned the economy of desulphurization system and the economy analysis on desulphurization system improving environmental quality.